This study aims to determine the relationship of dietary habits, psychosocial factors and physical fitness to the BP levels of children. It is difficult to study diet in relation to blood pressure levels in the USA because of the uniformity of US dietary practices. Seventh-day Adventists (SDAs) are a conservative religious group, many of whom adhere to unique dietary practices such as the avoidance of meat and caffeine and their exposure to, and mechanisms of coping with, stress may be considerably different from the general population. The study population consists of 1st-10th grade students attending SDA parochial schools as well as public schools. Approximately 9,000 students will initially be screened with 3 BP determinations. Detailed information on dietary habits, psychosocial factors and fitness levels as well as 9 BP measurements will then be obtained at school from all students in the extremes (1,200) of their respective age-sex distribution and a sample (600) of those with intermediate levels. Similar information, as well as BP measurements (x 3) will also be obtained from parents of this sample of students. Parent-child pairs which are markedly discordant or concordant on BP level will be studied in greater depth. We will also be able to observe whether changes in BP occur in a sample of SDA students who experience marked change in dietary habits and social environment by transferring to SDA boarding schools. The population will include adequate numbers of comparable persons of 3 ethnic groups (Blacks, Mexican-Americans, Whites) who range in dietary habits from spartan pure vegetarians to the extremes of the typical American diet. Psychosocial traits may also be widely discrepant in segments of this population. Thus this study holds great promise of identifying modifiable dietary or psychosocial factors related to elevated BP in both children and adults.